Sleep setup · Side sleepers

Why Side Sleepers Are Switching to a Butterfly-Shaped Pillow

If you sleep on your side and keep folding your pillow in half or tucking an arm under it, the shape of the pillow may be the thing that doesn't fit you.

Updated September 2026 · 4 min read

Woman sleeping on her side on a butterfly-shaped memory foam pillow in a bright bedroom with a tropical view

The gap a regular pillow leaves

When you lie on your side, your shoulder lifts your head well above the mattress. A regular rectangular pillow is built flat, and a soft one gets squashed thin by morning. That leaves your head tilting down toward the mattress instead of lining up with the rest of your body.

Most side sleepers fix this without thinking: they fold the pillow, stack two, or slide an arm underneath to prop their head up. The arm trick is the one many people recognize. You wake up with that arm "asleep" and have to shake it back to life.

None of this is about buying a softer or fluffier pillow. It's about shape: a pillow that is higher where your neck and shoulder need it, and that leaves room for your arm.

What the butterfly shape does differently

The pillow getting attention for this is the Derila Ergo, a contoured memory foam pillow shaped like a butterfly. Instead of one flat surface, it's built in zones:

Woman resting on her back on the butterfly-shaped memory foam pillow in a bright bedroom with a tropical view — The raised "wings" and lower center are what set it apart from a flat pillow.

Raised side wingsExtra height on the sides, where a side sleeper's head rests, to fill the gap above the shoulder.

Central areaA lower middle section for when you roll onto your back.

Arm support areaA cut-out on the side so your arm can rest under the edge instead of under your head.

Ear / headphone gapA small space so your ear isn't pressed flat against the foam.

Contoured memory foamA molded foam shape instead of loose fill that shifts around during the night.
Side and back sleepingThe support changes as you move from the side wings to the center.
Removable, washable coverThe breathable cover comes off for washing.
SizeAbout 21.2 × 14.1 in (54 × 36 cm).

Smiling young woman sitting on a bed holding a light-blue butterfly-shaped memory foam pillow

See the pillow, the bundle options and today's price on the official page.

Check Today's Price →Opens the official order page

What buyers say

The brand's Trustpilot page shows a 4.1 out of 5 rating from more than 45,000 reviews (checked September 2026). Positive reviews mostly talk about comfort and support when sleeping on the side or back. Critical reviews most often mention that the foam is firmer than expected, delivery times, and the return process, which is why we list those details below.

Before you order: the honest details

It feels firm at first. Contoured memory foam takes some getting used to. The maker suggests giving it about a week of nights before judging it.
One size. It comes in one size and one height.
Shipping takes a while. US delivery is typically 8–12 business days.
60-day return window. You can return it within 60 days. Return shipping is paid by the customer, and the original shipping fee isn't refunded, so check the full return terms on the order page.

Is it worth trying?

If you sleep mostly on your side and your current pillow ends up folded, doubled or propped on your arm every night, a shaped pillow like this addresses exactly that. If you sleep mostly on your stomach or prefer a very soft, squishy pillow, this probably isn't the right style for you.

Check availability and current bundle pricing.

See the Butterfly Pillow →60-day return window

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